И. А. Курбасова Е. И. Силантьева

THE RAILROAD TRACK

I

The track is one of the basic features of a railway. It is also called the permanent way. The fact is that¹ in the early days of railroad building the workers first had to lay temporary tracks to transport the materials to the construction site. And only after that they laid down the permanent tracks or the permanent way, as it was called. The permanent way consists of rails, ties, and ballast.

The railroad track of today is quite different from that used in the early days of railways. The first tracks had no ballast, the rails were made of wood and rested on heavy blocks of granite. Then the wooden rails were replaced by iron ones, and the granite blocks were re­placed by wooden ties or sleepers. This kind of track, how­ever, was not strong enough for heavy steam trains. The discovery how to make cheap steel was of great impor­tance to the railways for, when placed in the same track, steel rails had a life 15 times as long as iron rails.

The distance between the rails is called the gauge. The standard gauge in most countries is 1,435 mm while in the Soviet Union the railroads have a gauge of 1,524 mm. That gauge was finally adopted when the first main-line Moscow—St. Petersburg railway was under construction (1842-1851). Thus Russia was the world's first country where the uniform gauge was adopted for all railways. In America, the gauge was unified only in 1886.

The place where the ends of the rails meet in the track is known as the rail joint. The rail joint' has always been the weakest part of the track for nearly all the rails wear out first' at the ends.

Some railroads have two or more tracks. In order to make the trains pass from one track to another the railroads have a switch which is a very important ele­ment of the track.

II

The rails differ greatly in weight according to the kind of traffic which they have to carry when placed in the track. The largest and heaviest rails are laid in the main-line tracks for it is these tracks which carry the larg­est volume of traffic.

The ties on most tracks were almost all of wood and in order to make them last longer they were treated with creosote.

The ties are not laid upon the earth for the earth cannot support the track structure. They rest upon a bed of crushed rock or gravel, which is called ballast. Ballast is a very important element of the track for it is the bal­last which supports the track structure, holds the track in position and provides needed drainage.

The history of railways is more than one century and a half. During this period the track structure has been substantially irrr^V6ved. One of the greatest improve­ments was the elimination of rail joints. In order to re­duce the number of joints the rails are welded into contin­uous lengths. These continuous or long-welded rails have greater strength and provide a smoother running of trains at far greater speeds.

Another improvement which has made it possible to increase speeds on railways is the use of concrete sleep­ers. Thus in some countries, concrete sleepers have re­placed wooden ones on heavily used main lines because of their advantages. Concrete sleepers have a longer life and a far greater weight than those made of wood. The great­er weight of concrete sleepers provides the greater stabil­ity of track. It is this factor which has greatly contribut­ed to increased speeds.